I had to rig my squirrel cage fan to use the carbon scrubber as an intake, and it's not recommended, cuz they burn out this way. BUT, there is ZERO odor, besidez ONA all around my flowering room. But when you open the door, DAMN STINKY! I'm either going to order a can fan, or rig my 12" attic fan to two 6" scrubbers.